ghsa-m42m-m8cr-8m58
Vulnerability from github
The HTMLSectionSplitter class in langchain-text-splitters is vulnerable to XML External Entity (XXE) attacks due to unsafe XSLT parsing. This vulnerability arises because the class allows the use of arbitrary XSLT stylesheets, which are parsed using lxml.etree.parse() and lxml.etree.XSLT() without any hardening measures. In lxml versions up to 4.9.x, external entities are resolved by default, allowing attackers to read arbitrary local files or perform outbound HTTP(S) fetches. In lxml versions 5.0 and above, while entity expansion is disabled, the XSLT document() function can still read any URI unless XSLTAccessControl is applied. This vulnerability allows remote attackers to gain read-only access to any file the LangChain process can reach, including sensitive files such as SSH keys, environment files, source code, or cloud metadata. No authentication, special privileges, or user interaction are required, and the issue is exploitable in default deployments that enable custom XSLT.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "langchain-text-splitters"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.3.9"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-6985"
],
"database_specific": {
"cwe_ids": [
"CWE-611"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-07T21:32:54Z",
"nvd_published_at": "2025-10-06T18:15:52Z",
"severity": "HIGH"
},
"details": "The HTMLSectionSplitter class in langchain-text-splitters is vulnerable to XML External Entity (XXE) attacks due to unsafe XSLT parsing. This vulnerability arises because the class allows the use of arbitrary XSLT stylesheets, which are parsed using lxml.etree.parse() and lxml.etree.XSLT() without any hardening measures. In lxml versions up to 4.9.x, external entities are resolved by default, allowing attackers to read arbitrary local files or perform outbound HTTP(S) fetches. In lxml versions 5.0 and above, while entity expansion is disabled, the XSLT document() function can still read any URI unless XSLTAccessControl is applied. This vulnerability allows remote attackers to gain read-only access to any file the LangChain process can reach, including sensitive files such as SSH keys, environment files, source code, or cloud metadata. No authentication, special privileges, or user interaction are required, and the issue is exploitable in default deployments that enable custom XSLT.",
"id": "GHSA-m42m-m8cr-8m58",
"modified": "2025-10-08T14:07:35Z",
"published": "2025-10-06T18:31:07Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-6985"
},
{
"type": "WEB",
"url": "https://github.com/langchain-ai/langchain/pull/31819"
},
{
"type": "WEB",
"url": "https://github.com/langchain-ai/langchain/commit/43eef435505a1c907227b724c0c760ad5fc01790"
},
{
"type": "PACKAGE",
"url": "https://github.com/langchain-ai/langchain"
},
{
"type": "WEB",
"url": "https://huntr.com/bounties/cf78abbb-df3b-43de-b6ee-132b73ff8331"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "LangChain Text Splitters is vulnerable to XML External Entity (XXE) attacks due to unsafe XSLT parsing"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.